Ultra-thin copper foil (<8µm)

South Korean specialty materials company (KRX: 020150, HQ Anyang, Gyeonggi-do; ILJIN Group subsidiary); Korea's largest battery copper foil manufacturer, producing electrolytic copper foil at 6-12µm for Li-ion battery anode current collectors. ILJIN Materials operates the IKBC (ILJIN Korea Battery Copper) brand for Samsung SDI, LG Energy Solution, and SK On — the three Korean battery giants that collectively manufacture cells for BMW, Volkswagen, GM, Ford, and Stellantis EVs. ILJIN Materials also has copper foil production in Malaysia (ILJIN Malaysia) for Southeast Asian supply chain diversification. ILJIN Group is a Korean conglomerate spanning ball bearings (automotive), diamond tools (construction), and copper foil — the same Korean conglomerate that makes the bearings in your car's wheel hub also makes the copper foil in its battery. ILJIN Materials was the first Korean company to commercialize battery-grade electrolytic copper foil.

Japanese electrical conglomerate (TSE: 5802), co-inventor of VAD (Vapor Axial Deposition) preform process in 1977 with NTT and Fujikura. Primary optical fiber preform and drawing facility at Mie Works (Kameyama City, Mie Prefecture), which received IEEE Milestone recognition and switched to 100% renewable energy (announced October 2023). Launched the world's highest-fiber-count cable (13,824-fiber) from Mie Works No. 2 plant (February 2026). US operations via OFS Fitel (Norcross/Carrollton/Avon GA) — OFS and Hengtong formed a JV (Jiangsu OFS Hengtong Optical Technology, Suzhou, est. 2010) to produce VAD preforms in China. Furukawa is one of the world's most vertically integrated optical fiber companies: preform → fiber → cable → connectivity.

South Korean battery copper foil manufacturer (KRX: 009190, HQ Jeongup, Jeonbuk; SK Group subsidiary since 2020 when SK Innovation acquired Nexilis from KCFT Group); produces electrolytic copper foil at 6-10µm for EV battery anode current collectors. SK Nexilis supplies SK On (SK Group's battery subsidiary) and other Korean battery makers. SK Group's acquisition of Nexilis (copper foil) complemented its SK On (battery cells) and SK Materials (semiconductor gases, battery electrolyte) positions — building a Korean battery materials vertical from foil to electrolyte to cell. SK Nexilis is expanding production in Poland (to serve European battery gigafactories) and the US (IRA incentives). The same SK Group behind SK Hynix (world's 2nd-largest memory chip maker), SK Telecom (Korean mobile network), and SK Energy (Korea's largest oil refiner) also makes the copper foil in EV batteries.